Gul 2.0 is a powerfull and free Xul parser/interpreter library for Phpgtk 2 written in php. Gul supports PHP and basic CSS features into Xul. Gulpad example provides a split screen where the Xul code can be typed and immediately previewed.
Command-line option parser: PHP5 port/rewrite of Console_Getopt, with added functionalities, and with a Web interface to run getopt-like shell commands through a browser (not implemented yet).